[Setting normal levels of benz(a)pyrene in foods].

In the paper, methodological requirements are formulated for validation of permissible levels of benz(a)pyrene (B(a)P) in foodstuffs. A list is submitted of allowable levels of this carcinogen in food products for the population of Ukraine, their specific values being dependent on the accepted tolerance daily done intake and on the structure of the standard food ration. Prevention of B(a)P formation and its elimination from the human habitat together with the use of the modern environmentally appropriate technologies designed to prepare food products will form a basis for stabilization of the permissible dose of the carcinogen, finding its way to the human body as a food component through dietary intake.

[Methodological issues of standardization of environmental carcinogenic agents].

The paper considers the basic methodological principles for standardization of environmental carcinogenic agents. It shows it necessary to take into account carcinogenic hazards presented by environmental chemical pollutants. Emphasis is laid to the standardization of these substances in terms of the combined and complex action.

[Oncologic hygienic aspects of regulation of benz(a)pyrene in food products].

The paper presents a methodological scheme for regulating the acceptable levels of benz(a)pyrene in the foodstuffs is presented. It also gives a list of the acceptable levels of this carcinogen in the foodstuffs whose specific values depend on its daily dosage and the pattern of a standard diet for the Ukraine's population.

[Hygienic aspects of the study of the synthesis of nitrosamines from their precursors].

The paper presents data on the content of nitrosamines (NA), such an nitrosodimethylamine, nitrosodiethylamine, and their precursors (NO2 and amines) in the ambient air of different functional zones of a city. A high correlation between NA and NO2 in the air was established. NO2 was shown to have the leading role as a nitrosating agent in the model system and air during exogenous synthesis.

[Content of carcinogenic substances in the oil-refrigerating technology].

Benz(a)pyrene and nitrosamines serve as bases for oiling refrigerating technologic mediums. Such mediums applied to metals processing lead to higher carcinogens content and their release into the air of working area. Studies demonstrate that employees are exposed to effective doses of carcinogens.

[Nitrosamine levels in the environmental air of several large cities].

Data of studies on the content of nitrosodimethylamine, nitrosodiethylamine and nitrogen oxides in the air medium of certain cities with different degrees of industrial development are presented in the paper. The dynamics of the concentrations of chemicals under study during the annual cycle is shown. A correlation between the content of those chemicals in the air medium and the main meteorological factor is established.

[Experimental study of combined effects of benzo(a)pyrene and ortho-cresol on the body].

Ortho-cresol (o-cresol) produces a modifying influence on the effect produced by benz/a/pyrene (BP) under mice CC57B exposure to the combined peroral administration of the two chemicals. A low-toxic dose of o-cresol (Img) abruptly activates the effect of the same dose of BP (1 mg) according to all parameters (increase of the frequency, coefficient of multiplicity and degree of malignancy of tumours, shortening of the latency period) and somewhat inhibits its activity when administered before or after BP. Simultaneous administration of o-cresol in a ++super-toxic dose (10 mg) and BP in an optimal dose (5 mg) does not change the frequency of tumours, as compared to the control, however, inhibits the progression of induces neoplasms, which is manifest in the decrease of the frequency of malignancy, multiplicity of appearance and lengthening of the time of the onset of their malignization.

[Experimental substantiation of MPEL of dibenz(a,n)anthracene in atmospheric air].

Overt dependence of lung tumour development on the values of the dose administered was shown in experiments on inbred white rats under intratracheal administration of various doses of dibenz (a, h) anthracene (DBA); minimal-effect dose and maximal no-effect dose of DBA were established in the experiment. A theoretically calculated allowable dose was used to calculate MAC of the chemical under study for the ambient air 5 ng/m3 was recommended as an average 24-hour maximum allowable concentration of DBA in ambient air.

[The modifying effect of ortho-cresol on benzo(a)pyrene-induced carcinogenesis in mice].

A modifying influence of ortho-cresol (o-cresol) on the carcinogenic effect of benzo(a)pyrene (B(a)P) in their combined peroral administration to CC57Br mice has been revealed. During the simultaneous administration of the o-cresol (1 mg) and B(a)P (1 mg) the rate of tumours, their multiplicity index, the degree of malignancy increased and the latent period shortened. In case of o-cresol administration before or after B(a)P (in the same doses) the decrease of carcinogenic effect has been revealed.